© 2026 Sinochem Nanjing Corporation,
All Right Reserved
2,4-Dichlorobenzoic acid stands as a specialty chemical with a prominent profile in organic synthesis, crop protection, and material science. This compound, with molecular formula C7H4Cl2O2 and CAS Number 50-84-0, belongs to the group of chlorinated aromatic acids. Its structure reveals a benzene ring substituted at the 2 and 4 positions with chlorine atoms, and a carboxylic acid group attached to the 1-position. The result of this configuration: a pale, off-white solid presenting itself in crystalline, powder, or sometimes flaked and granular forms depending on the manufacturing process and requested specification.
Holding a molecular weight of 191.01 g/mol, 2,4-dichlorobenzoic acid displays a density of about 1.555 g/cm3. In solid state, it forms prismatic crystals or fine flakes, often available as a dry powder for ease in formulation. The melting point sits between 155°C and 159°C, reflecting excellent heat stability within normal process conditions for pharmaceuticals or agrochemicals. This acid has limited solubility in water, dissolving better in organic solvents such as ethanol, ether, and chloroform. The substantial presence of chlorine atoms heightens its hydrophobic character and drives powerful intermolecular interactions, which impact both reactivity and compatibility with other chemicals.
In both flakes and powder forms, the substance remains stable under recommended storage conditions—dry, cool, and protected from direct sunlight. On exposure to open air, little to no volatility has been observed due to low vapor pressure. In liquid or slurry formats, it may be handled as a solution in appropriate organic solvents for precise dosing or synthesis. The acid may present as pearls for select bulk applications, but this form is far less common than crystal, solid, or powder configurations. Crystal purity often exceeds 98 percent for chemical synthesis use. Its HS Code falls under 29163990, reflecting classification within carboxylic acid derivatives and halogenated aromatic compounds.
In my own work with chlorinated aromatic compounds, safety stands out as a top priority. 2,4-dichlorobenzoic acid counts as a hazardous material due to its irritant profile and potential for harmful effects if inhaled, swallowed, or in contact with skin and eyes. The chemical may cause respiratory discomfort, eye and skin irritation, and carries environmental hazards, especially for aquatic life. Avoiding dust generation, using proper ventilation, and wearing personal protective equipment like gloves, goggles, and dust masks becomes non-negotiable in any serious laboratory or industrial setting. Spills demand careful cleanup with absorbent material, followed by thorough washing of exposed surfaces using standard chemical decontamination procedures.
Transport requires compliance with local chemical handling regulations and guidelines for substances considered hazardous. Labeling must indicate risk to health and environment. Fire response suggests use of dry chemical, CO2, or foam extinguishing agents since the material does not mix readily with water and may react under extreme heat to produce noxious fumes. Although 2,4-dichlorobenzoic acid holds moderate toxicity, chronic exposure, particularly in poorly ventilated workspaces, should be avoided to limit long-term health impacts.
Chemists value this compound for its dual role: as an intermediate in the synthesis of more complex organic molecules, and as a raw material in the preparation of active pharmaceutical ingredients, dyes, and especially plant protection agents. Its sharp reactivity, thanks to the electron-withdrawing effect of chlorine, lets it participate in a range of substitution, coupling, and acylation reactions. In my past projects, using 2,4-dichlorobenzoic acid granted considerable latitude for selective functionalization—vital for the custom manufacture of specialty herbicides and fungicides. Given its low solubility in water, it persists longer in some environmental contexts, impacting application strategies in formulation development.
The solid and powder forms integrate directly into process lines, while solutions allow for measured dispensing in batch or continuous synthesis. The acid supports the production of esters, amides, and other derivatives, giving rise to tailored chemical entities that meet technical needs in agriculture and health. Its use stretches to the creation of liquid crystal intermediates and specialty coatings, where its chlorinated backbone adds desirable performance features such as resistance to degradation and alterations in refractive index.
Manufacturing standards draw strict lines around impurity profiles, typically setting minimum purity requirements above 98 percent with trace metals, unreacted parent compounds, and residual solvents kept within agreed limits. Analytical techniques like HPLC, titration, and melting point measurement confirm identity and batch consistency. Labs track water content, often under 0.5 percent by Karl Fischer detection. Distributors assign HS Code 29163990 for customs and global trade. In my own quality audits, issues generally focus on particle size control, elimination of color contaminants, and clear documentation of all synthesis and storage steps, matching regulatory expectations for pharmaceutical and agrochemical supply chains.
All transport and storage follow material safety data sheet (MSDS) guidance, which spells out necessary precautions for short- and long-distance movement, warehouse practices, and in-plant transfer procedures. Labels include all required pictograms and precaution statements for international compliance.
Producers use chlorination of benzoic acid with controlled process conditions, balancing reagent purity, temperature, and reaction time to boost yield and minimize environmental impact. Waste streams from this chemistry contain chloride byproducts that must be managed carefully to avoid regulatory penalties. Supply chains sourcing 2,4-dichlorobenzoic acid focus on consistent origin of raw materials and tight process controls at each manufacturing step, helping buyers predict performance and minimize supply interruptions. As global demand increases in specialty chemicals and crop protection, strategic stockholding and strong supplier relationships matter more than ever.
To maintain best performance, users store the acid in tightly closed containers, shielded from moisture and sunlight, at temperatures below 25°C. Given the compound’s resistance to microbial attack, chemical stability stretches to several years under these conditions, though material safety reviews recommend reassessment after three years. For waste, careful segregation and use of registered hazardous disposal facilities prevents harmful release to the environment. Many facilities opt to collect and incinerate waste under controlled conditions, capturing chlorinated emissions before atmospheric entry.
In the hands of skilled chemists and careful managers, 2,4-dichlorobenzoic acid unlocks routes to complex molecules across multiple sectors. As always, staying on top of storage, handling, and regulatory control ensures both product quality and user safety. Success here, as I have found through years working with similar compounds, comes down to a blend of respect for the chemical’s potential, strict compliance with rules, and an eye for continuous process improvement from the lab bench to the loading dock.
